Apparatus for case-hardening and other metal treatment.



A. W. MAGHLETf APPARATUS FOR CASE HARDENING AND OTHER METAL TREATMENT.

- AI PLIOATIOII FILED MAY 28, 1906. 1,933,815.

Patented July 30, 1912.

ATTO

WITNESSES ADOLPH W. MACH LET, 01E ELIZABETH, NEW- JERSEY.

APPARATUS FOR. CASE-HARDENING OTHER METAL TREATMENT.

Specification of Letters Patent. Patgnted July 30 1912, Application filed May 28, 1906. Serial No. 319,124. 1

To all tohom'tt may concern:

Be it known that I, ADoLPH \V. Mxci-nle'r,

a citizen of the United States, residing in of New Jersey, have invented -certain new and useful Improvements inApparatus for Case-Hardening and other Metal Treatment, of which the following is a specification.

This invention relates to the heating of metal articles, simultaneously with other treatment thereof, so to anneal or otherwise change the condition of the articles.

The object of the invention is to provide simple, inexpensive and easily operatedmeans for subjecting articles to a high degree of heat, and securing uniformity of heat throughout all portions of the'articles; and further to provide means for simultaneously subjecting the articles to the action of any desired gas..-

In carrying out the invention, I provide a furnace, preferably employing mixed air and gas as a fuel, and mount wholly within the furnace a cylindrical retort or barrel, to containthe art'icles to beheatedgand I provide means for efiecting rotation of the retort during the heating thereof. The retort is mounted wholly within the flame chamber of the furnace, sothat it is evenly heated throughout during its rotation, and hence the articles are uniformly heated, which is a feature of importance in many processes. The retort'is provided with ends, one of which is 1n the form of a lid; and in the form of the invention herein illustrated,

both said ends are confined between the ends of the furnace. One of the furnace ends is in-the formof a removable plug. adjacent to the lid. of the retort; thus giving access to the latter, for"charging or dischargingthe retort. Theretort is also removably mounted within the Wornout it may readily be replaced. *Inthe form-of the inventionfherein shown, the retort isrevolubly mounted upon' rolls which are mounte d outside of 'the' furnace, but. which extend through openings'formed in thewalls of the furnace,'so that the retort rests'upon the rolls. Upon the retort peripheral the rolls; to prevent endwise displacement of theretort. I

" In'the'accompanying drawings, Figure 1 is a longitudinal sectional elevation of one. form of apparatus for carrying out myimof the furnace,

the plug.

furnace," so that when flanges are provided, engaged by provements. Fig. 2 is a cross-section of the main portion of the apparatus.

The form of furnace lllustrated 1s cyl1ndrical comprising a tubular metal cover '1,

and a tnick cylindrical lining 2 of refractory material, the fiamechamber being seen at 3. The framework of the furnace also comprises ends 4, 5, having thicklinings 6," 7. The lining 6 is in the form of. a cylindrical plug fitted in a seat 8 in-the left hand end and having a metal cap 9 to which are attached handles 10 for removing The heat is supplied by. a series of burners for mixed air and gas, said series extendingtheentire length of the furnace, as indicated diagrammatically. at 11, and directed downwardly and tangentially ofthe cylindrical fire chamber. The burners are inserted in tangential holes 12 in the side wall of the furnace, and are connected to a feed pipe 18, which extends the length of the v 9 furnace.

A cylindrical retort 14f containing the articles 15 to be heated, is mounted within the retort upon two pairs of rolls 16 and 17. The rolls are fixed upon shafts 18, extending along theunder sides of the fur supported upon "standards 19. I e retort nearly fills the flame chamber, so that only a narrow annular space is left'b'etween theretort and the lining of the furnace. The burners .11 and the holes 12' areso placed as ace and to direct the flames around said annular space instead of causing them to lmplnge directly against the retort, thereby securing Each of the even heating of the latter. shafts 18 extends beyond the end 1 of the furnace, and is provided with a worm wheel 2O engaged by a power-driven worm 21 for rotating the rolls 16, 17 upon each shaft, and thereby causing the retort to turn. The

'walls of the furnac'e'are provided with openings as at 22, through whichthe rolls 16, -17 1 extend into the furnace. Upon theretort, which is 'preferably of cast, iron are cast a pair of fianges 23, between which the rolls 17 'ride,"and'by which endWise displacement of the retort is prevented. The rolls 16 ride directly-"upon the peripheryofthe retort-and permit slight endwise movement of theleft hand'en'd of the retort due toits gradual permanent elongation. The: ends of the re tort 2 1-. 25, are inthis instance confined between the ends 6', 7, of the furnace; the end 25 being cast upon the retort, and the end the furnace being provided to support said 24 being in the nature'of a lidv which is secured by any suitable devices, as for instance bolts 26 engaging a' flange 27 upon the retort. This lid 24 is adjacent to the cover 6 of the furnace, and is provided with a han dle 28, which protrudesthrough an opening- 29 formed in the cover 6. From the opposite e'nd of the furnace extends a pipe 30 connected by"a gland 31 to a supply pipe 32; a bracket 32 secured upon the end 50f gland. The pipe 32 is connected to a tank, holder, or boiler, for inert gas or steam, the passage of which into the retort is controlled by a valve 34.

The described structure may be employed for the uses set forth in my co-pe'nding applications Nos. 244,244 filed Feb. 4, 1905,

255,355, filed April 13, 1905, 292,515, filed Dec; 19, 1905, 292,626, filed Dec. 20, 1905, and 317,315, filed May 17, 1906. Some of the claims herein broadly cover what is shown in-said applications, but the claims in the latter do not cover the specific form of the invention herein illustrated. When the apparatus is to be used for casehardening, as set forth in certain of said ap- I burizing heat. In-this mannerthe cement- -ing operation may be hastened. Moreover,

heating the articles in anordinary heating furnace is more economical of fuel than heating them in the retort itself, besides which there is 'less deterioration of the retort. in proportion .-to the quantity of case-hardening done therein. Moreover, cheaper fuel, as for instance coal may be employed for pre-heating the artic es. This process is'also suitable for small articles, viz., pre-heating them and then introduclng them into a heated retort; and-the latter may be kept in operation almost uninterruptedly effecting,

the cementation of repeated charges of articles, without delaying toheat up the articles from a cold state.

In case-hardenin by the apparatuses shown in this and said other applications, it is also practicable to secure a very tough shell upon the. case-hardened articles. They are first cemented by placing them in the retort, and exp'osin them to a current of ,carburizinggas whi e they are at carburizing heat. They may have been .preheated or not, accordin to requirements ;'and they may be cemented either by means of their own p're viously acquired heat, or the furnace may be kept in operation during the carburization, until shells or cases of high-carbon steel incase the articles, as explained in said applications. Preferably, however,.the cementation is done while 'the articles are at red heat, that is, at the lowest heat at which they can be cemented; this degree of heatbeing accurately secured and maintained by the use of said apparatuses. If, however,

the articles are cemented while at white heat,

they are allowed to cool gradually until they are-at red heat. The articles being at red heat, are quenched in oil (preferably fish oil). They are then again passed through the cementing operation; or the described operation is repeated, the, articles being againquencheclin oil. During this second cementing operation, the cementation may be allowed to. proceed toa greater depth upon the articles, or only to the original depth,.as may be desired. .The second quen'chingyas well asthe second cementation, may be done while the articles are at red heat. If desired, the operation may be repeated again, thus making three cementa-- tions, and the depth of the cementation may be increased at each repetition, or it may remain the same as by the first operation. In this manner, very tough cases are formed upon the articles, which is a great advantage for certain classes of articles, which are to K be subjected to repeated heavy shocks, "as

Preferablyfat each well as surface wear. operation the articles are re-heated in the so as to avoid loss of carbon from" the sur faces'of the articles, or other deterioration thereof. Articles quenched and re-cemented Zin this manner show a very fine fracture, and are very tough; L-They may be 0ther-- wise quenched; and it. is not necessary in all as they may 0001 cases .to' quench 1 them, slowly before re-heatingj r v ,The apparatus may also be employed for oxidizing steel, iron, copper-and other articles. For this purpose, the part 33-maybe retort while exposed to the carburizing'gas,

regarded asa steam boiler. The cover 6 is removed together with the lid- 24 and, the

articles 15. inserted. Y Then the lid 24 is ,re-

placed loosely, and steam-is admitted from .the boiler 33 through thepipe's 32 and 30,

the displaced airescaplng betweenthe lid,

2 1 and the end. of the retort. Then .the

"burners are lighted and the lid'24 isf'sec'ured tightly, and the. furnace 'is'closed by means of the cover 6. The retort isrheated until] the steam decomposes, whereuponthe oxygen' of the steam unites with the surface por-' tions of themetal articles, oxidizingzthem.

During the heating and oxidizingoperations, the retort is'kept' in 'slowrotation y means of the worm 21 and 'wormwlieel '22, so that I the retort and the articles therein are um formlyheated and the articles uniformly the revolving retort.

disposed to the oxidizing action of the decomposed steam. If desired, the articles may be allowed to cool before the retort is opened.

Many other. variations maybe resorted to within the scope of the invention, and portions of the improvements may be used with-' out others. j

Having thus described my invention, I claim:

1. In combination, a furnacehaving a flame chamber provided withclosed ends, a closed retort confined wholly .Witllin said chamber between said ends, and means extending within said flame chamber for revolubly supporting said retort by both of its ends. v

2. In combination, a furnace having a flame chamber, a closed retort wholly within said flame chamber, means extending. within said flame chamber. for revolubly supporting said retort, and means to conduct fluid into 3. In combination, a furnace having a I .fiame chamber, a closed retortwh olly within said flame chamber, and means extending wlthin said flame chamber for revolubly'supporting sald retort and preventing longitudinal displacement thereof; said retort being removably connected to said supporting means; and means to conduct fluid into the revolving retort. v i v 4. In combination, a furnace having a flame. chamber, a closed retortwholly confined within said chamber, 'means extending within said chamber for revolubly support-. ing the retort by both of its ends,pow'er driven means for effecting rotation "of the retort, and means to conduct fluid into the revolving retort.

5. In combinationfa furnace having a flame chamber a closed retort wholly within said flame chamber, rolls at eachside of the flame chamber, the retort being 'revolubly supported upon said rolls, and] means for turning one of the rolls, so as to cause the retort .to rotate. Y I 1 i i 6. In combination, a furnace having a flame chamber provided with ends, one of 'which is removable, and a closed retort wholly confined within said flame chamber betweensaid endsp 'rolls extending within the flame chamber to support" said retort, and'the latter being rem ovably mounted for revolution upon the rolls. a

7 .In; combination, a'fjfurnace having a flame chamber provided with ends, one of which is removable, a retortconfined within said flame chamber between said ends; rolls extending within theflame chamber to support said retort, and the latter being removably mounted for revolution upon the rolls, and a lid for the end of the retort which is adjacent tosaid removable end.

8. In combination, a furnace having a flame chamber -provided with'ends, one of rolls, and

ing a handle projecting .ber to support revolubly saidretort'; walls of the furnace havingopenings to re flame chamber, a closedrastfiiron retort which isremovable, a retort rolls alid for the U I is adjacent to said removableend,'and'means said lid for. supplynig'gas" to the retort, f

which is removable, a retort confined within said flame chamber between said ends; rolls extending within the flame chamber to sup-. 1 port'said retqrt', and thelatter being rv movably mounted for revolution upon th a lid for the end of the retor which is adjacent to said removable end.-tl latter having an opening, and saidlid has through said open ing. j

9. In. combination, a furnace having a flame chamber,"a closed retort wholly within said flame chamber, shafts mounted exteriorly of said furnace, and rolls on'fsai'dshafts, and extending within the flame'chamthe ceive said rolls. 10'. In combination a furnace comprising a bodyiand .endsand'having a thick refractory lining for said body and endsfone of said ends being removable, a cast iron Cy;

lindrical retort within; saidfurnace between said ends, and having 'a.lid in said'fur'nace adjacent .to the removable end of the latter, and a series of burnershfor mixed air and gas-let into the refractory lining of the body of the furnace, and directed'tangentially to the retort.

11. In combination, a fi'irnacehaving wholly within said chamber and having'pev ripheral flanges, power-drix -nrolls"upon which said retort is supported within "said chamber, said rolls engaging said flanges to prevent longitudinal displacement of theretort, and having axles outsidethe' body of the furnace.

12. In combination, a furnace having a flame chamber, a closed retort wholly within said flame chamber, means extending withing said flame chamber for revolubly sup N portingsaid retort, a'ndmeans for supplying I v gas to' said retort. j

13. In combination," a furnace havingflame chamber provided with endsflone or confinedwithi'n said flame chamber between said ends; rolls extending within the flame chamber to supportsaid retort, and the latter being -removably mounted for revolution upon the end of the "r'etort which connected to said'retort the end opposite I I 1 c I 1 114,111 combination, 'a'jfurnace haymgya flame, chamber, closed retort: "mounted whollywithin said flame chamber,.roll's 'ex' tending within the flairiechamb-erto revolubly support said retort, a holder for. inert fluid connected. to said retort, and power driven means for turning the retort during the. heating thereof. 7

l5. In'combination; a furnacei having a single flame chamber, a metallic retort 130.

' .wholly"within said chamber, a supporting means extending to I 'the'exterior of the furnace, said retort besaid supports,

and having and revolubleupon supports which are provided upon ing removably mounted at its ends upon said ends, a set, of burners for mixed air and fuel within said flame chamber, the

walls of r the latter cooperating with said burners to direct the flames with substantial uniformity beneath and around said retort, and a holder for inert fluidconnectedto said retort.

16. In combination, a furnace having a single chamber in which the flames origiwholly within mounted; the retort having at. one end a normally closed opening through hich the i with .a refractory lining, a metallic retort articles may be removed; and means for turning the retort during. the heating thereof.

' 17. In combination, a furnace having a body and ends, and having a refractory lining for said body and ends, said lining forming a single chamber inwhich the flames originate, a revoluble metallic retort wholly within said chamber, a holder for inert fluidconnected with said retort; said furnace being provided with rolls extending within the furnace and upon which the retort is so'mounted'that the flames may envelop the retort. throughout its length, said retort having at one end an opening to permit removal of the articles, 'saidopening having a rotating said retort.

18. In combination, a furnace provided having ends" and mounted wholly within said lining, numerous burners for mixed air and fuel, said burners. forming a set extend- I ing the entlre length of the retort, in'such a manner as to cause the retort to be heated throughout with. evenness independent of ,the-heat' of said refractory lining; means being provided for subjecting the articles in theretort to the action the retort foreifectl9.' In combination, .'a furnace having a provided with closed ends,'a

closed metallic retort wholly within said chamber between. said end'sand having a" removable cover at one end, means being 5 provided for 'revolubly supporting said retort duringthe heating thereof, said supand having a lid at-one.of

removable cover; and means for' chamber, a shaft supporting the rolls on:

i of inert gas during the heat-ing of the retort; and means independent of the ends of ing rotation of said retort.

body of the retort between its ends, and a holder for inert fluid connectedto one end of said retort, said furnace having an opening through which said'cover maybe removed, and also havingone end integral with the body and the other end provided with a removable cover, and a single pair of flanges cast upon provided with a lid for said. opening. I t 20. Awast barrel forming a retort and the body near one end to form a'track, a

pair of supporting rolls for said track, a

second pair of rolls supporting the other end of the body, and a furnace in Which'said retort is mounted.

21. A cast barrel formingret ort and having one end integral with the body and the other end provided with a removable cover, and a single pair of flanges cast upon the body near one end to form a-track,'a-

pair of supporting rolls for said track, a

said retort is mounted; said rolls mounted, outside f the furnace and prO eetmg' through the walls thereof into the flannechamber.

22'. A cast barrel forming a retort andhaving one end integral with thebody andv :the other end provided with a removable cover, and a single pair of flanges cast upon the body near one end to form a track, a pair of supporting rolls for said track, a

second pair of rolls supporting the other end of the body," and a furnace in'whil j second pair of rolls supporting the other end of the body, and a furnace iii-which said retort is mounted; 'saidrolls mounted outside of the furnace and projecting through the walls thereof into the flame one side of the furnace, and power driven gearing connected to said shaft.

23. The combination with a closed revoluble retort, of a furnace having-a: flame chamber within which the retort is wholly confined for revolution, said flame chamber having closed. ends between'which'the rebody and formed toidirect the'flames all I I around the same; said retort havinga removable cover atone end, andthe adjacent end of the furnace being..removable; andmeans to supply fluid intdt-he' other end of the retort; 4 i

ADOLPH 'W. MACHLET.

Witnessesiu SAMUEL R. OGDEN, PHILIP G. OSTERMAN. I 

